In a working vehicle in which the vehicle running speed is changed by the selective operation of plural fluid-operated clutches, it is already known from, for example, Japanese Patent No. 2,668,359 that plural direction control valves for controlling the supply of operating fluid individually to the plural fluid-operated clutches, particularly plural electromagnetic proportional direction control valves which permit the control of fluid pressure applied to the plural fluid-operated clutches, are employed for controlling the vehicle speed and that plural pressure sensors for sensing fluid pressure applied to the individual fluid-operated clutches electrically are employed for preventing abnormal double engagements of the fluid-operated clutches. However, there has not been provided yet a speed change control device which has such plural direction control valves and such plural pressure sensors in close proximity to the plural fluid-operated clutches in a compact manner and for an easy inspection and maintenance.
Accordingly, a primary object of the present invention is to provide a novel speed change control device in which plural direction control valves and plural pressure sensors are provided in close proximity to plural fluid-operated clutches in a compact manner and for an easy inspection and maintenance.